What Causes Blurry Vision?
Blurry, unclear vision is a common eyesight complaint. Blurry vision could just be a sign that your glasses or contacts prescription needs updating, or it could be a sign of something more serious. Blurry vision can be caused by a variety of conditions including the following:
Refractive Errors – For many patients with blurry vision, the cause is a refractive error, meaning that the lens in the front of the eye isn’t accurately focusing light on the retina in the back of the eye. There are several different kinds of refractive errors, each with similar but distinct symptoms:
- Myopia – Commonly called nearsightedness, this refractive error occurs when light is focused in front of the retina. With this condition, things nearby appear clear and in focus, but become increasingly blurry as distance between the object and the eye increases.
- Hyperopia – Also known as farsightedness, this condition is the opposite of nearsightedness. Hyperopia occurs when light is focused behind the retina, causing vision to become blurry the closer an object gets to the eyes.
- Astigmatism – This refractive error can be experienced in conjunction with myopia and hyperopia. It is a condition in which the eye is shaped irregularly, similar to a football, rather than a spherical shape, like a basketball.
- Presbyopia – This condition affects many people as they age, usually starting in the 40s or 50s, and is the result of weakened muscles around that eyes that are responsible for focusing light. Like astigmatism, this can occur on its own or with other refractive problems. Simple reading glasses can typically correct the issue, but when other refractory problems exist simultaneously, multifocal lenses may be needed to correct them all at once.
Temporary Causes – There are many causes of blurry vision that are temporary, only lasting a few months, weeks, days or even moments.
- Dry Eyes – Dry eyes can lead to irritation and discomfort as well as blurred vision. If the surface of the cornea becomes too dry, it may not allow light to pass through clearly, causing a blurring effect.
- Headaches – Migraines or even brief headaches can affect the muscles that focus the eyes as well as cause sensitivity to light.
- Medications – Some pills and medicated eye drops can affect the vision, either by weakening the muscles that focus the eye, or by depositing chemicals or substances on the surface of the cornea.
- Laser Eye Surgery – You may experience blurred vision immediately following any type of eye surgery as the eye begins to heal. This is common and nothing to worry about unless it persists for more than a few days.
- Allergies – Seasonal or environmental allergies can affect the eyes making them feel itchy, watery, appear red and blur vision.
- Contact Lenses – The goal of contact lenses is to make vision clearer, not blurry. However if the lenses aren’t handled properly, blurry vision may result.
More Serious Causes of Blurry Vision
In rare cases, blurry vision may be a symptom of a more serious underlying condition such as: